// Copyright 2018 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.

package rpc

import (
	"github.com/ethereum/go-ethereum/log"
	"net"
)

// StartHTTPEndpoint starts the HTTP RPC endpoint, configured with cors/vhosts/modules
func StartHTTPEndpoint(endpoint string, apis []API, modules []string, cors []string, vhosts []string) (net.Listener, *Server, error) {
	// Generate the whitelist based on the allowed modules
	whitelist := make(map[string]bool)
	for _, module := range modules {
		whitelist[module] = true
	}
	// Register all the APIs exposed by the services
	handler := NewServer()
	for _, api := range apis {
		if whitelist[api.Namespace] || (len(whitelist) == 0 && api.Public) {
			if err := handler.RegisterName(api.Namespace, api.Service); err != nil {
				return nil, nil, err
			}
			log.Debug("HTTP registered", "namespace", api.Namespace)
		}
	}
	// All APIs registered, start the HTTP listener
	var (
		listener net.Listener
		err      error
	)
	if listener, err = net.Listen("tcp", endpoint); err != nil {
		return nil, nil, err
	}
	go NewHTTPServer(cors, vhosts, handler).Serve(listener)
	return listener, handler, err
}

// StartWSEndpoint starts a websocket endpoint
func StartWSEndpoint(endpoint string, apis []API, modules []string, wsOrigins []string, exposeAll bool) (net.Listener, *Server, error) {

	// Generate the whitelist based on the allowed modules
	whitelist := make(map[string]bool)
	for _, module := range modules {
		whitelist[module] = true
	}
	// Register all the APIs exposed by the services
	handler := NewServer()
	for _, api := range apis {
		if exposeAll || whitelist[api.Namespace] || (len(whitelist) == 0 && api.Public) {
			if err := handler.RegisterName(api.Namespace, api.Service); err != nil {
				return nil, nil, err
			}
			log.Debug("WebSocket registered", "service", api.Service, "namespace", api.Namespace)
		}
	}
	// All APIs registered, start the HTTP listener
	var (
		listener net.Listener
		err      error
	)
	if listener, err = net.Listen("tcp", endpoint); err != nil {
		return nil, nil, err
	}
	go NewWSServer(wsOrigins, handler).Serve(listener)
	return listener, handler, err

}

// StartIPCEndpoint starts an IPC endpoint
func StartIPCEndpoint(isClosedFn func() bool, ipcEndpoint string, apis []API) (net.Listener, *Server, error) {
	// Register all the APIs exposed by the services
	handler := NewServer()
	for _, api := range apis {
		if err := handler.RegisterName(api.Namespace, api.Service); err != nil {
			return nil, nil, err
		}
		log.Debug("IPC registered", "namespace", api.Namespace)
	}
	// All APIs registered, start the IPC listener
	var (
		listener net.Listener
		err      error
	)
	if listener, err = CreateIPCListener(ipcEndpoint); err != nil {
		return nil, nil, err
	}
	go func() {
		for {
			conn, err := listener.Accept()
			if err != nil {
				// Terminate if the listener was closed
				if isClosedFn() {
					log.Info("IPC closed", "err", err)
				} else {
					// Not closed, just some error; report and continue
					log.Error("IPC accept failed", "err", err)
				}
				continue
			}
			go handler.ServeCodec(NewJSONCodec(conn), OptionMethodInvocation|OptionSubscriptions)
		}
	}()

	return listener, handler, nil
}